/* 第一讲的目的主线。颜色沿用课程；蓝图、路线与注释承担信息关系。 */
.meaning-page { width: 100%; max-width: 1280px; margin: auto; display: flex; flex-direction: column; justify-content: center; gap: clamp(24px, 3.2vh, 38px); }
.meaning-page .head { max-width: 1040px; }
.meaning-page .lede { max-width: 54em; }
.meaning-page h2 { font-size: clamp(1.25rem, 1.45vw + .4rem, 1.72rem); line-height: 1.45; letter-spacing: -.025em; }
.meaning-page p { line-height: 1.8; }
.meaning-label { font-size: .78rem; letter-spacing: .06em; color: var(--muted); margin-bottom: 12px; }
.t-ink .meaning-label { color: var(--on-ink-2); }
.meaning-link { display: inline-flex; align-items: center; justify-content: space-between; gap: 20px; text-align: left; min-height: 42px; border-bottom: 1px solid currentColor; font-size: .92rem; padding: 5px 0; }
.meaning-link span { font-size: 1.1rem; }
.meaning-link:hover { color: var(--blue); }
.t-ink .meaning-link:hover { color: var(--mark); }
.meaning-primary { background: var(--mark); color: var(--ink); border: 0; padding: 12px 22px; min-height: 48px; }
.meaning-primary:hover, .t-ink .meaning-primary:hover { background: var(--mark-2); color: var(--ink); }
.meaning-footnote { color: var(--muted); font-size: .84rem; }
.t-ink .meaning-footnote { color: var(--on-ink-2); }
.meaning-cover { display: grid; grid-template-columns: 1.1fr 1fr; grid-template-rows: 1fr auto; gap: 42px 7%; align-items: center; padding: 12px 0; }
.meaning-kicker { display: flex; flex-wrap: wrap; align-items: center; gap: 24px; font-size: 1rem; margin-bottom: 26px; }
.meaning-kicker span { color: var(--on-ink-muted); padding-left: 24px; border-left: 1px solid var(--line-ink-2); }
.meaning-cover h1 { font-size: clamp(3.6rem, 6.3vw, 6.1rem); line-height: 1.12; letter-spacing: -.065em; font-weight: 600; }
.meaning-cover h1 em { color: var(--mark); font-style: normal; }
.meaning-cover-lede { margin-top: 26px; font-size: clamp(1.08rem, 1.2vw, 1.25rem); color: var(--on-ink-2); }
.meaning-cover-actions { display: flex; flex-wrap: wrap; gap: 20px 28px; align-items: center; margin-top: 32px; }
.meaning-cover-drawing { position: relative; display: grid; grid-template-columns: 1fr; gap: 0; padding: 34px 36px 24px; border-left: 1px solid var(--line-ink-2); background-image: radial-gradient(var(--line-ink) .8px, transparent .8px); background-size: 16px 16px; }
.meaning-cover-drawing small { display: block; color: var(--on-ink-muted); font-size: .78rem; margin-bottom: 6px; }
.meaning-cover-drawing strong { display: block; font-size: clamp(1.22rem, 1.6vw, 1.72rem); line-height: 1.5; font-weight: 500; }
.meaning-origin { justify-self: start; border-left: 3px solid var(--mark); padding-left: 16px; }
.meaning-drawing-arrow { font-size: .75rem; color: var(--on-ink-muted); margin: 12px 0 12px 30%; }
.meaning-drawing-arrow span { display: inline-block; transform: rotate(45deg); font-size: 1.3rem; margin-left: 16px; }
.meaning-making { justify-self: center; padding: 15px 23px; background: var(--ink-2); border: 1px solid var(--line-ink-2); }
.meaning-making strong { color: var(--mark); }
.meaning-making p { font-size: .8rem; margin-top: 5px; color: var(--on-ink-2); }
.meaning-result { justify-self: end; text-align: right; }
.meaning-return { border-top: 1px dashed var(--line-ink-2); margin-top: 22px; padding-top: 12px; font-size: .76rem; color: var(--on-ink-muted); }
.meaning-cover-footer { grid-column: 1 / -1; border-top: 1px solid var(--line-ink-2); padding-top: 18px; font-size: .86rem; color: var(--on-ink-2); letter-spacing: .1em; }
.meaning-route { border-top: 1px solid var(--line-2); }
.meaning-route li { display: grid; grid-template-columns: 52px 1fr 82px; align-items: center; gap: 20px; padding: 14px 0; border-bottom: 1px solid var(--line); }
.meaning-route li > span { font: .9rem var(--mono); color: var(--muted); }
.meaning-route li > div { display: grid; grid-template-columns: 160px 1fr; gap: 24px; align-items: baseline; }
.meaning-route h2 { font-size: 1.17rem; }
.meaning-route p { font-size: .99rem; color: var(--text-2); }
.meaning-route .meaning-link { border: 0; }
.meaning-reading { font-size: .92rem; color: var(--text-2); }
.meaning-definition { display: flex; align-items: center; gap: 26px; border-top: 1px solid var(--line-2); border-bottom: 1px solid var(--line-2); padding: 18px 0; }
.meaning-definition p { flex: 1; }
.meaning-definition b { display: block; font-size: 1.12rem; margin-bottom: 3px; }
.meaning-definition p span { color: var(--text-2); font-size: .91rem; }
.meaning-definition-join { flex: 0 0 205px; max-width: 205px; color: var(--muted); font-size: .8rem; text-align: center; }
.meaning-demo { border: 1px solid var(--line-2); }
.meaning-step-tabs { display: flex; border-bottom: 1px solid var(--line-2); padding: 0 24px; }
.meaning-step-tabs button { flex: 1; min-height: 62px; font-size: 1rem; position: relative; display: flex; align-items: center; gap: 10px; }
.meaning-step-tabs button > span { width: 24px; height: 24px; border: 1px solid var(--line-2); display: inline-grid; place-items: center; font: .78rem var(--mono); border-radius: 50%; }
.meaning-step-tabs button[aria-pressed="true"]::after { content: ''; position: absolute; bottom: -1px; left: 0; right: 18px; height: 3px; background: var(--text); }
.meaning-step-tabs button[aria-pressed="true"] > span { background: var(--mark); border-color: var(--mark); }
.meaning-step-tabs i { color: var(--muted); font-style: normal; margin-left: auto; margin-right: 24px; }
.meaning-demo-body { display: grid; grid-template-columns: 1.35fr 1fr; gap: 48px; padding: 28px; min-height: 238px; }
.meaning-demo-body h2 { margin-bottom: 14px; }
.meaning-demo-body > div > p:last-child { font-size: 1.06rem; color: var(--text-2); }
.meaning-demo-body aside { border-left: 1px solid var(--line-2); padding-left: 28px; }
.meaning-demo-evidence { font-size: 1.17rem; font-weight: 500; }
.meaning-demo-result { font-size: .88rem; color: var(--text-2); margin-top: 18px; }
.meaning-architecture { display: grid; grid-template-columns: 1.1fr 1fr; gap: 5%; align-items: start; }
.meaning-blueprint { padding: 12px 24px 22px; border: 1px solid var(--line-ink-2); background-image: radial-gradient(var(--line-ink) .65px, transparent .65px); background-size: 16px 16px; }
.meaning-node { text-align: center; padding: 12px 18px; background: var(--ink-2); border: 1px solid var(--line-ink-2); }
.meaning-node b { display: block; font-size: 1.04rem; font-weight: 500; }
.meaning-node small { display: block; color: var(--on-ink-2); font-size: .76rem; }
.meaning-node[aria-pressed="true"], .meaning-harness-label[aria-pressed="true"], .meaning-framework button[aria-pressed="true"] { color: var(--ink); background: var(--mark); border-color: var(--mark); }
.meaning-node[aria-pressed="true"] small { color: var(--text-2); }
.meaning-goal { display: block; margin: 8px auto 0; min-width: 58%; }
.meaning-arrow-down { text-align: center; font-size: .78rem; color: var(--on-ink-2); padding: 10px 0; }
.meaning-harness { border: 1px dashed var(--line-ink-2); padding: 16px; }
.meaning-harness-label { padding: 5px 8px; margin: -4px 0 16px -4px; font: .86rem var(--mono); text-align: left; border: 1px solid transparent; }
.meaning-harness-label span { font: .74rem var(--sans); opacity: .7; margin-left: 8px; }
.meaning-cycle { display: grid; grid-template-columns: 1fr auto 1fr; gap: 8px; align-items: center; }
.meaning-cycle .meaning-node { padding: 12px 8px; }
.meaning-flow-arrow { max-width: 54px; font-size: .68rem; text-align: center; color: var(--on-ink-2); }
.meaning-return-arrow { padding: 10px 0 7px; color: var(--on-ink-2); font-size: .78rem; text-align: center; }
.meaning-feedback { display: block; width: 100%; }
.meaning-framework { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; border-top: 1px solid var(--line-ink-2); margin-top: 18px; padding-top: 14px; font-size: .72rem; color: var(--on-ink-2); }
.meaning-framework button { padding: 5px 8px; border: 1px solid var(--line-ink-2); font: .82rem var(--mono); }
.meaning-framework b { font: .72rem var(--sans); margin-left: 8px; }
.meaning-architecture-detail { padding: 18px 0; }
.meaning-architecture-detail > p:not(.meaning-label) { font-size: 1.02rem; color: var(--on-ink-2); margin-top: 20px; }
.meaning-architecture-detail blockquote { border-left: 3px solid var(--mark); padding-left: 18px; margin: 26px 0; font-size: 1.12rem; line-height: 1.75; }
.meaning-architecture-detail .meaning-link { font-size: .86rem; }
.meaning-levels { display: grid; grid-template-columns: .85fr 1.15fr; gap: 5%; align-items: stretch; }
.meaning-level-nav { border-top: 1px solid var(--line-2); }
.meaning-level-nav button { display: grid; grid-template-columns: 34px 1fr 20px; align-items: center; gap: 16px; width: 100%; text-align: left; padding: 13px 14px 13px 0; border-bottom: 1px solid var(--line-2); }
.meaning-level-nav button > span { font: .78rem var(--mono); color: var(--muted); }
.meaning-level-nav small { display: block; font-size: .78rem; color: var(--muted); }
.meaning-level-nav b { font-size: 1.07rem; font-weight: 500; }
.meaning-level-nav i { font-style: normal; }
.meaning-level-nav button[aria-pressed="true"] { background: var(--mark); padding-left: 14px; }
.meaning-level-nav button[aria-pressed="true"] small, .meaning-level-nav button[aria-pressed="true"] > span { color: var(--text-2); }
.meaning-level-detail { padding: 12px 0; }
.meaning-level-detail h2 { max-width: 18em; }
.meaning-level-detail > p:not(.meaning-label) { margin-top: 18px; font-size: 1.06rem; color: var(--text-2); }
.meaning-level-example { border-left: 3px solid var(--text); padding-left: 20px; margin-top: 28px; }
.meaning-level-example .meaning-label { margin-bottom: 8px; }
.meaning-level-example blockquote { font-size: 1.06rem; line-height: 1.8; }
.meaning-level-links { display: flex; flex-wrap: wrap; gap: 10px 26px; margin-top: 24px; }
.meaning-launch { display: grid; grid-template-columns: .95fr 1.05fr; gap: 5%; align-items: start; }
.meaning-launch-form { display: grid; gap: 14px; }
.meaning-launch-form label { display: grid; gap: 7px; }
.meaning-launch-form label > span { font-size: .94rem; font-weight: 500; }
.meaning-launch-form input, .meaning-launch-form textarea { display: block; width: 100%; min-width: 0; background: transparent; border: 1px solid var(--line-2); border-radius: 0; padding: 10px 12px; font-size: .91rem; line-height: 1.65; resize: vertical; }
.meaning-launch-form input::placeholder, .meaning-launch-form textarea::placeholder { color: var(--muted); }
.meaning-launch-form .meaning-link { justify-self: start; font-size: .85rem; }
.meaning-launch-output { padding-left: 24px; border-left: 1px solid var(--line-2); }
.meaning-launch-output > .meaning-label { margin-bottom: 10px; }
.meaning-launch-output .prompt textarea { height: 325px; min-height: 325px; max-height: 390px; font-size: .89rem; line-height: 1.75; }
.meaning-launch-output .meaning-footnote { margin-top: 14px; }
@media (min-width: 761px) {
  .meaning-blueprint { padding-bottom: 18px; }
  .meaning-blueprint .meaning-node { padding-top: 9px; padding-bottom: 9px; }
  .meaning-arrow-down { padding: 6px 0; }
  .meaning-harness { padding: 12px; }
  .meaning-harness-label { margin-bottom: 10px; }
  .meaning-return-arrow { padding: 6px 0 4px; }
  .meaning-framework { margin-top: 12px; padding-top: 10px; }
}
@media (max-width: 1050px) {
  .meaning-cover { gap: 34px; }
  .meaning-cover-drawing { padding: 24px; }
  .meaning-route li > div { grid-template-columns: 140px 1fr; gap: 14px; }
  .meaning-demo-body { gap: 26px; }
  .meaning-blueprint { padding-left: 14px; padding-right: 14px; }
}
@media (max-width: 760px) {
  .meaning-page { gap: 26px; }
  .meaning-cover { display: flex; gap: 32px; align-items: stretch; }
  .meaning-cover h1 { font-size: clamp(3.6rem, 13vw, 5rem); }
  .meaning-cover-drawing { border-left: 0; border-top: 1px solid var(--line-ink-2); }
  .meaning-cover-footer { letter-spacing: 0; }
  .meaning-route li { grid-template-columns: 26px 1fr 56px; gap: 12px; }
  .meaning-route li > div { display: block; }
  .meaning-route h2 { margin-bottom: 5px; }
  .meaning-route p { font-size: .9rem; }
  .meaning-route .meaning-link { gap: 4px; font-size: .8rem; }
  .meaning-definition { display: grid; gap: 15px; }
  .meaning-definition-join { max-width: none; text-align: left; }
  .meaning-demo-body, .meaning-architecture, .meaning-levels, .meaning-launch { grid-template-columns: 1fr; gap: 24px; }
  .meaning-step-tabs { padding: 0 12px; }
  .meaning-step-tabs button { flex-direction: column; justify-content: center; gap: 5px; min-height: 72px; font-size: .85rem; }
  .meaning-step-tabs i { display: none; }
  .meaning-step-tabs button[aria-pressed="true"]::after { right: 0; }
  .meaning-demo-body { padding: 20px; }
  .meaning-demo-body aside { border-left: 0; border-top: 1px solid var(--line-2); padding-left: 0; padding-top: 18px; }
  .meaning-cycle { grid-template-columns: 1fr auto 1fr; }
  .meaning-cycle .meaning-node { padding-left: 4px; padding-right: 4px; }
  .meaning-node small { text-wrap: balance; }
  .meaning-architecture-detail { padding: 0; }
  .meaning-level-detail { padding-top: 0; }
  .meaning-launch-output { padding-left: 0; padding-top: 22px; border-left: 0; border-top: 1px solid var(--line-2); }
}
@media (prefers-reduced-motion: reduce) {
  .meaning-page *, .meaning-page *::before, .meaning-page *::after { scroll-behavior: auto; }
}